Explosively operated industrial tools utilizing cartridges having explosive powder and a primer for detonating the powder are disclosed in U.S. Pat. Nos. 3,007,409 and 3,155,039. Both of these patents disclose cartridges that include a gas check member that has one end adjacent the explosive powder and the other end facing outwardly with a detonator primer therein. An opening communicates between the primer and the explosive powder. A ram is arranged so that it can be made to slide into the open end of the cartridge, strike the primer, thereby igniting the explosive powder. Such tools, however, under certain conditions, allow the primer to be ejected from the cartridge into the interior of the tool after firing. In an attempt to solve this problem, a deforming gas check member was devised that would deform under the heat and forces generated during firing to retain the primer within the gas check member. Such a deforming gas check member is disclosed in U.S. Pat. No. 4,913,055, which teaches a two part plastic gas check member having a metal washer therebetween. During firing, a portion of the gas check member and the primer are temporarily caught between the ram and the washer and deformed so that the primer is retained within the gas check member. However, under certain circumstances this structure allows some of the expanding gases to penetrate the deforming plastic gas check member and pass completely through into the interior of the tool. These escaping gases will contaminate the tool and reduce the amount of force available at the end of the ram, sometimes to the point of compromising the performance of the tool. As the gas is expanding and pushing the gas check and the ram toward the work piece, the steel washer causes the primer to expand which in turn causes the gas check to expand. This occasionally causes the shell to expand outwardly a sufficient amount to wedge itself in the bore of the barrel, making it difficult to remove. Additionally, during assembly of this deforming gas check, a relatively high degree of dimensional accuracy must be maintained which tends to increase the cost of manufacture and results in a lower reliability of the cartridge.
What is needed is a structure that will positively retain both the primer and the detonator cap within the gas check member under these conditions without other adverse effects.